The present invention relates generally to an information search system for searching for multimedia data, and more particularly to a system for searching for multimedia data based on fixed-pattern data such as a mark mounted in the multimedia data.
In recent years, WWW (World Wide Web) systems have become popular for utilizing networks such as the Internet. A WWW system comprises WWW servers each for providing a variety of information, and client terminals connected to the WWW servers through the Internet for receiving information provided therefrom. The respective WWW servers open their unique Web pages, such that a user can access a Web page by specifying URL (Uniform Resource Locater) corresponding to the Web page to a browser program running on a client terminal. The browser can display multimedia data such as text, image data, video data, audio data and so on included in the Web page thus acquired on a display device of the client terminal. A Web page is described using a structural description language called HTML (Hyper Text Mark-up Language), so that another Web page can be accessed through its URL set in a Web page.
When a client searches Web pages with a certain purpose, the client must access a Web page of a WWW server which provides a search service, and request for a key word search or specify a Web page which may satisfy the purpose of the client with reference to a link list provided by the search service. The link list refers to a Web page which collectively has a plurality of listed link destinations of Web pages previously selected in accordance with an intention of an editor.
While a Web page is a copyrighted work, a client, once acquiring the Web page, can readily create duplicates and deliver the duplicates through the Internet. For preventing unauthorized copies of digital data sent through the Internet in this way, xe2x80x9celectronic watermarkxe2x80x9d techniques have been proposed for embedding ID information, a logo mark or the like of an author within a copyrighted work in secrecy.
According to the prior art search techniques mentioned above, it is not easy to search Web pages published by particular authors, Web pages highly evaluated by Web page evaluating organizations, and so on. Even if a search service provided on the WWW is utilized to conduct a key word search, this may result in a problematic situation which presents search missing that fails to include desired Web pages in a search result, and search noise that includes unwanted information. In addition, when existing link lists cannot be utilized, a client must create his own link list. However, creation of a link list involves describing link data to selected Web pages using the HTML, and so on. This work implies a problem in that a large number of work steps is required and the created list cannot flexibly support changes in Web pages, if any. Furthermore, it is also difficult to distinguish normally published Web pages from forged or tampered Web pages.
It is an object of the present invention to provide a system for searching only for normal multimedia data without relying on a key word search or creation of a link list, and a program for executing such a search.
Multimedia data handled by the present invention is assumed to be mounted with fixed-pattern data such as a logo mark, which is embedded with code information that is difficult for human to perceptually recognize. A program on a server for managing such fixed-pattern data embeds specified code information in specified fixed-pattern data in response to a request from the outside, and sends the fixed-pattern data to a requester. Then, the program registers a database with information related to multimedia data mounted with the code information, in correspondence to the code information, searches the database based on specified code information in response to a search request from a client, extracts information related to multimedia data corresponding to the specified code information, and sends the extracted information to a requester. A program on the client side in turn decodes code information embedded in fixed-pattern data mounted in multimedia data, issues to the management server a search request for information related to associated multimedia data based on the code information, and displays acquired information related to the associated multimedia data on a display device.